There are lots of things to consider when you buy bed sheets: Are they strong? Will they wrinkle? How easy are they to get on the mattress? But first and foremost, they need to be soft and comfortable if they truly are high quality sheets.

While percale and linen sheets usually feel more crisp, like hotel sheets, they’re not ideal if you’re looking for the softest sheets. These materials make the softest bed sheets:

• Sateen: The yarn in one direction floats over several yarns in the opposite direction, giving this type of weave a smoother feel than a basic, grid-like percale. When it comes to 100% cotton, our testers tend to prefer sateen for its softness.
• Flannel: The surface of flannel fabric is brushed so it traps in air to keep you warm, but that process also makes it feel soft and cozy.
• Microfiber: These sheets are made of super thin polyester fibers and give a buttery-smooth feel. They won’t feel as natural as cotton sheets, but they’re usually much less expensive.
• Rayon: This fiber is regenerated cellulose – meaning it’s partially natural and partially synthetic – but the outcome is a silky smooth and incredible soft. You’ll sometimes see this written in variations like viscose (which means the same thing) or lyocell (which follows a more sustainable process).

Be aware that thread count doesn’t really matter when it comes to soft sheets: Cotton sateen is the only one from this list that’ll have a valid thread count (i.e. the number of yarns per square inch of fabric). Thread count is not a top priority when you shop for sheets because the fiber content and weave are also important, but a higher thread count can sometimes make sheets softer. (The sweet spot in our test is usually in the 300-500 range.)